He looked at Khalid. 'Do you see what I mean?'
'Maybe,' Khalid said. 'You propose to chart movement with numbers.'
'Yes, and also the movement within movement, changes in speed, you know, which must always be occurring in this world, as there is resistance or encouragement.'
'Resistance of air,' Khalid said luxuriously. 'We live at the bottom of an ocean of air. It has weight, as the mercury scales have shown. It bears down on us. It carries the beams of the sun to us.'
'Which warm us,' Bahram added.
The sun cracked the distant mountains to the east, and Bahram said, 'All praise and thanks to Allah for the glorious sun, sign in this world of his infinite love.'
'And so,' Khalid said, yawning hugely, 'to bed.'
A Demonstration of Flight
Inevitably, however, all their various activities brought them another visit from Nadir Devanbegi. This time Bahram was in the bazaar, sack over his shoulder, buying melons, oranges, chickens and rope, when Nadir suddenly appeared before him with his personal bodyguard. It was an event Bahram could not regard as a coincidence.
'Well met, Bahram. I hear you are busy these days.'
'Always, effendi,' Bahram said, ducking his head. The two bodyguards were eyeing him like falcons, wearing armour and carrying long barrelled muskets.
'And these many fine activities must include many undertaken for the sake of Sayyed Abdul Aziz Khan, and the glory of Samarqand?'
'Of course, effendi.'
'Tell me about them,' Nadir said. 'List them for me, and tell me how each one is progressing.'
Bahram gulped apprehensively. Of course Nadir had nabbed him in a public place like this because he thought he would learn more from Bahram than from Khalid or Iwang, and more in a public space, where Bahram might be too flustered to prevaricate.
So he frowned and tried to look serious but foolish, not really much of a stretch at this moment. 'They do much that I don't understand, effendi. But the work seems to fall roughly into the camps of weapons and of fortifications.'
Nadir nodded, and Bahram gestured at the melon market they were standing beside. 'Do you mind?'
'Not at all,' Nadir said, following him in.
So Bahram went to the honey and muskmelon trays, and began to lift some onto the scale. He was certainly going to get a good deal for them with Nadir Devanbegi and his bodyguards in the shop!
'In weapons,' Bahram improvised as he pointed out the red melons to a sullen seller, 'we are working on strengthening the metal of cannon barrels, so they can be both lighter and stronger. Then again, we have been conducting demonstrations of the flight of cannonballs in different conditions, with different gunpowders and guns, you know, and recording them and studying the results, so that one would be able to determine where precisely one's shots would land.'
Nadir said, 'That would be useful indeed. Have they done that?'
'They are working on it, effendi.'
'And fortifications?'
'Strengthening walls,' Bahram said simply. Khalid would be furious to hear of all these promises Bahram was so rashly making, but Bahram did not see any good way out of it, except to make his descriptions as vague as possible, and hope for the best.
'Of course,' Nadir said. 'Please do me the courtesy of arranging one of these famous demonstrations for the court's edification.' He caught Bahram's eye to emphasize this was not a casual invitation. 'Soon.'
'Of course, effendi.'
'Something that will get the Khan's attention as well. Something exciting to him.'
'Of course.'
Nadir gestured with a finger to his men, and they moved off through the bazaar, leaving behind a swirling wake in the press of the crowd.
Bahram heaved a deep breath, wiped his brow. 'Hey there,' he said sternly to the seller, who was slipping a melon off the scale.
'Not fair,' the seller said.
'True,' Bahram said, 'but a deal's a deal.'
The seller couldn't deny it; in fact he grinned under his moustache as Bahram sighed again.
Bahram went back to the compound and reported the exchange to Khalid, who growled to hear it, as Bahram knew he would. Khalid finished eating his evening meal in silence, stabbing chunks of rabbit out of a bowl with a small silver prong held in his left hand. He put the prong down and wiped his face with a cloth, rose heavily. 'Come to my study and tell me exactly what you said to him.'
Bahram repeated the conversation as closely as he could, while Khalid spun a leather globe on which he had tried to map the world. Most of it he had left blank, dismissing the claims of the Chinese cartographers he had studied, their golden islands swimming about in the ocean to the east of Nippon, located differently on every map. He sighed when Bahram finished. 'You did well,' he said. 'Your promises were vague, and they follow good lines. We can pursue them more or less directly, and they may even tell us some things we wanted to know anyway.'
'More demonstrations,' Bahram said.
'Yes.' Khalid brightened at the thought.
In the weeks that followed, the furore of activity in the compound took a new turn. Khalid took out all the cannons he had obtained from Nadir, and the loud booms of the guns filled their days. Khalid and Iwang and Bahram and the gunpowder artisans from the shop fired the big things west of the city on the plain, where they could relocate the cannonballs, after shots aimed at targets that were very seldom struck.
Khalid growled, picking up one of the ropes they used to pull the gun back up to the mark. 'I wonder if we could stake the gun to the ground,' he said. 'Strong ropes, thick stakes… it might make the balls fly farther.'
' We can try it.'
They tried all manner of things. At the end of the days their ears rang with reverberations, and Khalid took to stuffing them with cotton balls to protect them some little bit.
Iwang became more and more absorbed in the flights of the cannonballs. He and Khalid conferred over mathematical formulas and diagrams that Bahram did not understand. It seemed to Bahram they were losing sight of the goal of the exercise, and treating the gun merely as a mechanism for making demonstrations of motion, of speed and the change of speed.
But then Nadir came calling with news. The Khan and his retinue were to visit the next day, to witness improvements and discoveries.
Khalid spent the entire night awake in his study, making lists of demonstrations to be considered. The next day at noon everyone congregated on the sunny plain beside the Zeravshan River. A big pavilion was set up for the Khan to rest under while he observed events.
He did so lying on a couch covered with silks, spooning sherbet and talking with a young courtesan more than watching the demonstrations. But Nadir stood by the guns and watched everything very closely, taking the cotton out of his ears to ask questions after every shot.
'As to fortifications,' Khalid replied to him at one point, 'this is an old matter, solved by the Frengis before they died. A cannonball will break anything hard.' He had his men shoot the gun at a wall of dressed stone that they had cemented together. The ball shattered the wall very nicely, and the Khan and his party cheered, although as a matter of fact both Samarqand and Bokhara were protected by sandstone walls much like the one that had just fallen.
' Now,' Khalid said. 'See what happens when a ball of the same size, from the same gun loaded with the same charge, strikes the next target.'
This was an earthen mound, dug with great effort by Khalid's expuffers. The gun was fired, the acrid smoke cleared; the earthen mound stood unchanged, except for a barely visible scar at its centre.
'The cannonball can do nothing. It merely sinks into the earth and is swallowed up. A hundred balls would make no difference to such a wall. They would merely become part of it.'
The Khan heard this and was not amused. 'You're suggesting we pile earth all around Samarqand? Impossible! It would be too ugly! The other khans and emirs would laugh at us. We cannot live like ants in an anthill!'
Khalid turned to Nadir, his face a polite blank.<
br />
'Next?' Nadir said.
'Of course. Now see, we have determined that at the distances a gun can cast a ball, it cannot shoot straight. The balls are tumbling through the air, and they can spin off in any direction, and they do.'
'Surely air cannot offer any significant resistance to iron,' Nadir said, sweeping a hand in illustration.
'Only a little resistance, it is true, but consider that the ball passes through more than two li of air. Think of air as a kind of thinned water. It certainly has an effect. We can see this better with light wooden balls of the same size, thrown by hand so you can still see their movement. We will throw into the wind, and you can see how the balls dart this way and that.'
Bahram and Paxtakor palmed the light wooden balls off, and they veered into the wind like bats.
'But this is absurd!' the Khan said. 'Cannonballs are much heavier, they cut through the wind like knives through butter!'
Khalid nodded. 'Very true, great Khan. We only use these wooden balls to exaggerate an effect that must act on any object, be it heavy as lead.'
'Or gold,' Sayyed Abdul Aziz joked.
'Or gold. In that case the cannonballs veer only slightly, but over the great distances they are cast, it becomes significant. And so one can never say exactly what the balls will hit.'
'This must ever be true,' Nadir said.
Khalid waved his stump, oblivious for the moment of how it looked. 'We can reduce the effect quite a great deal. See how the wooden balls fly if they are cast with a spin to them.'
Bahram and Paxtakor threw the balsam balls with a final pull of the fingertips to impart a spin to them. Though some of these balls curved in flight, they went farther and faster than the palmed balls had. Bahram hit an archery target with five throws in a row, which pleased him greatly.
'The spin stabilizes their flight through the wind,' Khalid explained. 'They are still pushed by the wind, of course. That cannot be avoided. But they no longer dart unexpectedly when they are caught on the face by a wind. It is the same effect you get by fletching arrows to spin.'
'So you propose to fletch cannonballs?' the Khan inquired with a guffaw.
'Not exactly, your Highness, but yes, in effect. To try to get the same kind of spin. We have tried two different methods to achieve this. One is to cut grooves into the balls. But this means the balls fly much less far. Another is to cut the grooves into the inside of the gun barrel, making a long spiral down the barrel, only a turn or a bit less down the whole barrel's length. This makes the balls leave the gun with a spin.'
Khalid had his men drag out a smaller cannon. A ball was fired from it, and the ball tracked down by the helpers standing by, then marked with a red flag. It was farther away than the bigger gun's ball, though not by much.
' It is not distance so much as accuracy that would be improved,' Khalid explained. 'The balls would always fly straight. We are working up tables that would enable one to choose the gunpowder by type and weight, and weigh the balls, and thus, with the same cannons, of course, always send the balls precisely where one wanted to.'
'Interesting,' Nadir said.
Sayyed Abdul Aziz Khan called Nadir to his side. 'We're going back to the palace,' said, and led his retinue to the horses.
'But not that interesting,' Nadir said to Khalid. 'Try again.'
Better Gifts for the Khan
'I suppose I should make the Khan a new suit of damasked armour,' Khalid said afterwards. 'Something pretty.'
Iwang grinned. 'Do you know how to do it?'
'Of course. It's watered steel. Not very mysterious. The crucible charge is an iron sponge called a wootz, forged into an iron plate together with wood, which yields its ash into the mix, and some water too. Some crucibles are placed in the furnace, and when they are melted their contents are poured into molten cast iron, at a temperature below that of complete fusion of the two elements. The resulting steel is then etched with a mineral sulphate of one kind or another. You get different patterns and colours depending on which sulphate you use, and what kind of wootz, and what kind of temperatures. This blade here,' he rose and took down a thick curved dagger with an ivory handle, and a blade covered with a dense pattern of crosshatchings in white and dark grey, 'is a good example of the etching called "Mohammed's Ladder". Persian work, reputed to be from the forge of the alchemist Jundi Shapur. They say there is alchemy in it.' He paused, shrugged.
'And you think the Khan…'
'If we systematically played with the composition of the wootz, the structure of the cakes, the temperatures, the etching liquid, then we would certainly find some new patterns. I like some of the swirls I've got with very woody steel.'
The silence stretched out. Khalid was unhappy, that was clear.
Bahram said, 'You could treat it as a series of tests.'
'As always,' Khalid said, irritated. 'But in this case you can only do things in ignorance of their causes. There are too many materials, too many substances and actions, all mixed together. I suppose it is all happening at a level too small to see. The breaks you see after the casting look like crystalline structures when they are broken. It's interesting, what happens, but there's no way to tell why, or predict it ahead of time. This is the thing about a useful demonstration, you see. It tells you something distinct. It answers a question.'
' We can try to ask questions that steelwork can answer,' Bahram suggested.
Khalid nodded, still dissatisfied. But he glanced at Iwang to see what he thought of this.
Iwang thought it was a good idea in theory, but in practice he too had a hard time coming up with questions to ask about the process. They knew how hot to make the furnace, what ores and wood and water to introduce, how long to mix it, how hard it would turn out. All questions on the matter of practice were long since answered, ever since damasking had been done in Damascus. More basic questions of cause, which yet could be answered, were hard to formulate. Bahram himself tried mightily, without a single idea coming to him. And good ideas were his strength, or so they always told him.
While Khalid worked on this problem, Iwang was getting terrifically absorbed in his mathematical labours, to the exclusion even of his glassblowing and silversmithing, which he left mostly to his new apprentices, huge gaunt Tibetan youths who had appeared without explanation some time before. He pored over his Hindu books and old Tibetan scrolls, marking up his chalk slates and then adding to the notes he saved on paper: inked diagrams, patterns of Hindu numerals, Chinese or Tibetan or Sanskrit symbols or letters; a private alphabet for a private language, or so Bahram thought. A rather useless enterprise, disturbing to contemplate, as the paper sheets seemed to radiate a palpable power, magical or perhaps just mad. All those foreign ideas, arranged in hexagonal patterns of number and ideogram; to Bahram the shop in the bazaar began to seem the dim cave of a magus, fingering the hems of reality…
Iwang himself brushed all these cobwebs aside. Out in the sun of Khalid's compound he sat down with Khalid, and Zahhar and Tazi from Sher Dor, and with Bahram shading them and looking over their shoulders, he outlined a mathematics of motion, what he called the speed of the speed.
'Everything is moving,' he said. 'That is karma. The Earth revolves around the Sun, the Sun travels through the stars, the stars too travel. But for the sake of study here, for demonstrations, we postulate a realm of non movement. Perhaps some such motionless void contains the universe, but it doesn't matter; for our purposes these are purely mathematical dimensions, which can be marked by vertical and horizontal, thusly, or by length, breadth and height, if you want the three dimensions of the world. But start with two dimensions, for simplicity's sake. And moving objects, say a cannonball, can be measured against these two dimensions. How high or low, how left or right. Placed as if on a map. Then again, the horizontal dimension can mark time passed, and the vertical, movement in a single direction. That will make for curved lines, representing the passage of objects through the air. Then, lines drawn tangent to the curve indicate th
e speed of the speed. So you measure what you can, mark those measurements, and it's like passing through rooms of a house. Each room has a different volume, like flasks, depending on how wide and how tall. That is to say, how far, in how much time. Quantities of movement, do you see? A bushel of movement, a dram.'
'Cannonball flights could be described precisely,' Khalid said.
'Yes. More easily than most things, because a cannonball pursues a single line. A curved line, but not something like an eagle's flight, say, or a person in his daily rounds. The mathematics for that would be…' Iwang became lost, jerked, came back to them. 'What was I saying?'
'Cannonballs.'
'Ah. Very possible to measure them, yes.'
'Meaning if you knew the speed of departure from the gun, and the angle of the gun…'
'You could say pretty closely where it was going to land, yes.'
'We should tell Nadir about this privately.'
Khalid worked up a set of tables for calculating cannon fire, with artful drawings of the curves describing the flight of shot, and a little Tibetan book filled with Iwang's careful numerics. These items were placed in an ornate carved ironwood box, encrusted with silver, turquoise and lapis, and brought to the Khanaka in Bokhara, along with a gorgeous damasked breastplate for the Khan. The steel rectangle at the centre of this breastplate was a dramatic swirl of white and grey steel, with iron flecks very lightly etched by a treatment of sulphuric acids and other caustics. The pattern was called by Khalid the Zeravshan Eddies, and indeed the swirl resembled a standing eddy in the river, spinning off the foundation of the Dagbit Bridge whenever the water was high. It was one of the handsomest pieces of metalwork Bahram had ever seen, and it seemed to him that it, and the decorated box filled with Iwang's mathematics, made for a very impressive set of gifts for Sayyed Abdul Aziz.
He and Khalid dressed in their best finery for their audience, and Iwang joined them in the dark red robes and conical winged hat of a Tibetan monk, indeed a lama of the highest distinction. So the presenters were as impressive as their presents, Bahram thought; although once in the Registan, under the vast arch of the gold-covered Tilla Karia Madressa, he felt less imposing. And once in the company of the court he felt slightly plain, even shabby, as if they were children pretending to be courtiers, or, simply, bumpkins.
The Year of Rice and Salt Page 28
